On the Uniqueness of the Quasi-Moment-Method Solution to the Pathloss Model Calibration Problem

  • Hisham Abubakar Muhammed, Mr. Department of Electrical and Electronics Engineering, University of Lagos, Akoka, Lagos, Nigeria
  • Ayotunde Abimbola Ayorinde, Dr. Department of Electrical and Electronics Engineering, University of Lagos, Akoka, Lagos, Nigeria
  • Francis Olutunji Okewole, Engr. Department of Electrical and Electronics Engineering, University of Lagos, Akoka, Lagos, Nigeria
  • Michael Adedosu Adelabu, Dr. Department of Electrical and Electronics Engineering, University of Lagos, Akoka, Lagos, Nigeria
  • Ike Mowete University of Lagos

Abstract

Investigations in this paper focus on establishing the uniqueness properties of the Quasi-Moment-Method (QMM) solution to the problem of calibrating nominal radiowave propagation pathloss prediction models. Nominal (basic) prediction models utilized for the investigations, were first subjected to QMM calibrations with measurements from three different propagation scenarios. Then, the nominal models were recast in forms suitable for Singular Value Decomposition (SVD) calibration before being calibrated with both the SVD and QMM algorithms. The prediction performances of the calibrated models as evaluated in terms of Root Mean Square Prediction Error (RMSE), Mean Prediction Error (MPE), and Grey Relational Grade-Mean Absolute Percentage Error (GRG-MAPE) very clearly indicate that the uniqueness of  QMM-calibrations of basic pathloss models is more readily observable, when the basic models are recast in forms specific to SVD calibration. In the representative case of calibration with indoor-to-outdoor measurements, RMSE values were recorded for QMM-calibrated nominal models as 5.2639dB for the ECC33 model, and 5.3218dB for the other nominal models. Corresponding metrics for the alternative (rearranged) nominal models emerged as 5.2663dB for the ECC33 model and 5.2591dB for the other models. A similar general trend featured in the GRG-MAPE metrics, which for both SVD and QMM calibrations of all the alternative models, was recorded as 0.9131, but differed slightly (between 0.9138 and 0.9196) for the QMM calibration of the nominal models. The slight differences between these metrics (due to computational round-off approximations) confirm that when the  components of basic models are linearly independent, the QMM solution is unique. Planning for wireless communications network deployment may consequently select any basic model of choice for QMM-calibration, and hence, identify relative contributions to pathloss by the model’s component parts.

Author Biographies

Hisham Abubakar Muhammed, Mr., Department of Electrical and Electronics Engineering, University of Lagos, Akoka, Lagos, Nigeria

Hisham Muhammed received the B. Eng. and M. Sc. degrees in Electrical Engineering, from the University of Maiduguri (Nigeria) in 1991 and the University of Lagos, in 1998, respectively. He has been a lecturer at the University of Lagos (UNILAG) since 2002. His research interests extend over antennas and propagation, Biomedical Instrumentation, and software development. Muhammed’s draft Ph.D. thesis on “A matrix vector potential analysis of the bi-elliptical toroidal helical antenna”, is at about ready for oral examination.

Ayotunde Abimbola Ayorinde, Dr., Department of Electrical and Electronics Engineering, University of Lagos, Akoka, Lagos, Nigeria

Ayotunde Ayorinde received the B.Sc., M. Sc. and Ph.D. degrees in Electrical Engineering, from the University of Lagos, (UNILAG) Nigeria, in 1990, 1993, and 2009, respectively. His current research interests include electromagnetic fields, microwave engineering, antennas and propagation. Dr. Ayorinde, a Nigerian Registered Engineer, is a Senior Lecturer at the University of Lagos, and is also a member of the British Institution of Engineering and Technology (MIET)

Francis Olutunji Okewole, Engr., Department of Electrical and Electronics Engineering, University of Lagos, Akoka, Lagos, Nigeria

Francis Okewole was awarded the Bachelor of Technology (B. Tech.) Degree in Electrical Engineering, by the Ladoke Akintola University of Technology, Ogbomosho, Nigeria, in 2002, and obtained the degree of M. Sc. (also in Electrical Engineering) from the University of Lagos, in 2008. He is a Lecturer in the Department of Electrical and Electronics Engineering of the University of Lagos, and also a staff Ph.D. candidate, whose thesis on a hybrid MoM-PO analytical tool is ready for examination. Engr. Okewole has published a number of journal papers and conference proceedings papers in the area of antennas and radiowave propagation.

Michael Adedosu Adelabu, Dr., Department of Electrical and Electronics Engineering, University of Lagos, Akoka, Lagos, Nigeria

Michael Adelabu received the degree of M. Sc. in Electronics and Telecommunications from the Wroclaw Technical University in Poland in 1984, and Ph.D. (Electrical Engineering) from the University of Lagos in 2016. Dr. Adelabu is a Senior Lecturer in Electrical Engineering and has been with the University of Lagos since 1993. His current research interests extend to mobile communication networks and systems, radiowave propagation and spectrum management (efficient use). A fellow of the Nigerian Society of Engineers (FNSE), Dr. Adelabu is also a senior member of the IEEE

Published
01-07-2022
How to Cite
Muhammed, H., Ayorinde, A., Okewole, F., Adelabu, M., & Mowete, I. (2022). On the Uniqueness of the Quasi-Moment-Method Solution to the Pathloss Model Calibration Problem. Journal of Communication and Information Systems, 37(1), 109-120. https://doi.org/10.14209/jcis.2022.12
Section
Regular Papers